JPS582860B2 - Hydraulic control valve for two-line piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic control valve for two-system piping, which is used in a two-system hydraulic brake system of an automobile, and is used to limit an increase in output oil pressure with respect to an increase in inlet oil pressure for each system. It is something.

BACKGROUND OF THE INVENTION Brake systems that have two braking systems in automobiles to ensure safety in the event of brake failure are now in widespread use as a safety measure.

This type of safety brake device supplies oil from one hydraulic outlet of a tandem master cylinder to the front right wheel cylinder and rear left wheel cylinder, and supplies oil from the other hydraulic outlet to the front left wheel cylinder. The brake system is divided to supply the rear right wheel cylinder and two front left and right wheel cylinders each, and the hydraulic pressure coming from one hydraulic outlet of the tandem master cylinder is sent to one front left and right wheel. An effective method is to divide the brake system so that the hydraulic pressure is supplied to the cylinder and the rear left wheel cylinder, and the hydraulic pressure from the other hydraulic outlet of the tandem master cylinder is supplied to the other front left and right wheel cylinders and the rear right wheel cylinder. It has been put into practical use.

The former method is called X piping, and the latter method is called J-J piping, but in either piping method, the axle load distribution between the front and rear wheels changes during braking in the hydraulic pressure supply system to the rear wheel cylinder. Therefore, it is necessary to provide individual hydraulic control valves such as limiter valves or provisioning valves.

For this reason, the conventional two-system safety brake system requires two hydraulic control valves, which is extremely disadvantageous in terms of both installation space and assembly workability.

Therefore, as a hydraulic control valve for two-system piping, a pair of proportioning valves that individually control the hydraulic pressure of the rear wheel brake system are installed in parallel in one housing, and these proportioning valves are controlled by the above-mentioned predetermined hydraulic control. It has been proposed that the springs are energized through a common spring and spring seat so that this is carried out.

Therefore, the proportioning valve does not change the oil pressure at which it starts to limit the increase in the rear wheel brake oil pressure, that is, the critical oil pressure, and the front and rear wheel brake force distribution characteristics remain constant.

However, the ideal front and rear wheel brake force distribution characteristics, such as locking the front and rear wheels simultaneously, change as the vehicle weight increases, and the critical oil pressure needs to be increased as the vehicle weight increases.

In this sense, the above-described two-system piping hydraulic control valve in which a pair of proportioning valves are arranged side by side is not suitable for large trucks and the like where the vehicle weight changes greatly between when the vehicle is empty and when it is loaded.

In view of the above, the present invention provides a hydraulic control valve for two-system piping, which closes in response to deceleration of an automobile, and controls the amount of deflection of the common spring via a piston using the inlet hydraulic pressure corresponding to the deceleration. This paper proposes a hydraulic control valve for two-system piping, which is equipped with a deceleration-sensing valve that increases the critical hydraulic pressure in proportion to the increase in vehicle weight.

The present invention further provides that, in this type of hydraulic control valve, the hydraulic pressure of both systems is guided to the deceleration sensing type valve. A switching valve is installed in both artificial hydraulic pressure introduction passages to the speed sensing type valve, which closes the inlet hydraulic pressure introduction passage related to this system when one system fails, to avoid the above-mentioned inconvenience due to failure, and to detect deceleration even if only the normal system is used. Another feature is that this kind of hydraulic control valve for two-system piping is constructed so that the type valve can function and can compensate for the lack of braking force.

Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. FIG. 1 shows the entire hydraulic control valve of the present invention, in which a housing 1 is provided with a first plunger chamber 2 and a second plunger chamber 3. , 3 are arranged parallel to each other, and are opened at one end surface 1a of the housing 1.

The housing 1 further includes a first opening into the plunger chamber 2.
an inlet part 4 and a first outlet part 5, and a second inlet part 6 and a second outlet part 7 opening into the plunger chamber 3,
A first control valve 8 and a second control valve 9 are connected to the plunger chamber 2 to disconnect communication between the inlet portions 4, 6 and the outlet portions 5, 7, respectively.
, 3.

Both control valves 8 and 9 are bloating valves having exactly the same structure, and are constructed as described below.

That is, the plungers 10, 10' are inserted into the plunger chambers 2, 3, and the blind holes 11, 11' of the plungers 10, 10' are inserted.
A poppet valve body 12, 12' is disposed within.

Valve seats 13, 13' are caulked to the open ends of blind holes 11, 11', and poppet valve bodies 12, 12' are biased toward these valve seats by springs 14, 14'.

When the plungers 10, 10' move to the right from the illustrated position, the barbs 14, 14' hold the poppet valve bodies 12, 12' in the closed position, and at this time, the stem portions 15, 15' of the poppet valve bodies 12, 12' The lengths of the stem portions 15, 15' are determined so that they protrude from the left side of the valve seats 13, 13'.

The valve seats 13, 13' have plunger chambers 2, 3 and blind holes 11,
11' are bored through holes 16, 16' communicating with the blind hole 11.
, 11' and the inlet portions 4, 6 through holes 17, 17'.
are formed on the plungers 10, 10'.

The plunger chambers 2 and 3 have sleeves 18 that enclose the small diameter portions of the plungers 10 and 10' with a gap between them.
, 18' and a radial through hole 19 in this sleeve.
, 19' are provided, and through holes 19 in the radial direction from the inlet parts 4, 6 are provided.
, 19', through holes 17, 17', blind holes 11, 11', and through holes 16, 16' to form oil passages that reach the outlet portions 5, 7.

The plungers 10, 10' are made to protrude beyond the open ends of the plunger chambers 2, 3, and the protruding ends 10a, 10a' of the plungers 10, 10' are held by retainers 20, 20' fitted in the plunger chambers 2, 3. While guiding, seal 21,2
1' to seal.

Projecting ends 10a, 10a of the plungers 10, 10'
' is in contact with the spring seat 27.

The spring seat 27 consists of a spring seat body 22 and a push 24, and a resin push 2 is inserted into the center hole 22a of the spring seat body 22.
4 are fitted together.

The guide rod 23 is fixed to the housing 1, and has a seat plate 25 and the spring seat 2 disposed opposite each other with a gap at its free end.
A spring 26 is compressed between 7 and 7.

Thus, the spring 26 pushes the plungers 10, 10' of the control valves 8, 9 via the spring seats 27, and the poppet valve bodies 12, 1
2' is maintained in the valve open position separated from the valve seats 13, 13'.

The spring 26 and the spring seat 27 are housed in a cylindrical portion 41a that is integrally provided to a housing 41 of the deceleration sensing valve 40, and the housing 41 is coupled to the housing 1 via a seat plate 42.

A spring 43 is separately stored in the cylindrical portion 41a, and this spring is compressed between the spring seat 25 and the seat plate 42.

The housing 41 is formed with a cylinder chamber 44 and a ball chamber 45 that open to the cylindrical portion 41a, and a communication port 4 is provided between the two chambers.
6, and a rubber valve seat 47 is fixedly installed at the open end of the port 46 facing the chamber 45.

A piston 48 is slidably fitted into the cylinder chamber 44, and this piston is integrally molded with the spring seat 25.

The cylinder chamber 44 is further provided with an air vent valve 49 in communication with it.

A G ball 50 is fitted into the ball chamber 45, the ball chamber is closed with an end cover 51, and a groove 52 is formed in the ball chamber 45 to allow the spaces created before and after the G ball 50 to communicate with each other.

The housing 41 is further provided with a switching valve 53 which is normally kept in a position abutting against a stopper 55 by a spring 54 and allows the hydraulic inlet board 55 to communicate through the communication board 56 into the groove 52. , when it starts moving to the left in FIG. 1 against the spring 54, the hydraulic inlet board 57 is connected to the communication port 5.
6 and into the groove 52.

The hydraulic control valve of the present invention configured as described above is arranged at a predetermined angle θ with respect to the horizontal line 34 in the vehicle traveling direction so that the G ball 50 normally contacts the end cover 51 due to gravity and is separated from the valve seat 47.
Attach it to the vehicle body by tilting it upward.

In addition, the hydraulic control valve of the present invention connects the ports 55 and 57 to both hydraulic outlets of the tandem master cylinder 29, respectively, and connects the inlet portion 4 to one hydraulic outlet of the tandem master cylinder 29 together with the wheel cylinder 28 on the right side of the front wheel. To,
The outlet part 5 is connected to the wheel cylinder 30 on the left side of the rear wheel, the inlet part 6 is connected to the other hydraulic outlet of the cylinder master cylinder 29 together with the wheel cylinder 31 on the left side of the front wheel, and the outlet part 7 is connected to the other hydraulic outlet of the master cylinder 29.
are connected to the wheel cylinder 32 on the right side of the rear wheel.

This hydraulic control valve operates as follows by setting pressure receiving areas b1 and b2 (b1>b2) in the plungers 10 and 10'.

That is, when the master cylinder 29 is actuated by depressing the brake pedal 33 from the non-operating state shown in the figure, the master cylinders PM1 and PM2 move to the front wheel cylinders 28.3.
1 and is also fed into the inlet sections 4 and 6.

This master cylinder and hydraulic pressure were initially set to the poppet valve 12.
12' is open, the oil is directly supplied from the outlet portions 5 and 7 to the corresponding rear wheel cylinders 30, 32, and the front and rear wheel brake oil pressures rise with the characteristics shown by a-b in FIG.

At this time, the balance equation of the force applied to each plunger 10.10' is as follows, where the spring force of the spring 26 is F, PM・b2=1/2F (However, PM1=PM2=PM) (However, PM=PR1= PR2=PR).

Thereafter, when the force on the brake pedal 33 is increased and PM increases, and PM・b2>1/2F, the plungers 10 and 10' move against the spring 26, and the poppet valve 12 and 12' automatically closes. When closed, the communication between the inlets 4, 6 and the outlets 5, 7 is cut off, and the hydraulic pressure supply to the rear brake cylinders 30, 32 is cut off.

At the same time, the master cylinder oil pressure PM is adjusted to each plunger 10.
．． 10' is now exerted in the opposite direction, and the force balance equation becomes PM(b1-b2)+1/2F=PRb1.

From this balanced state, when the brake pedal 33 is further depressed to further increase the master cylinder oil pressure PM, the plunger 10, 10' returns to its original position, and the poppet valve 12
, 12' are opened again, and as the master cylinder oil pressure PM increases, the hydraulic pressure increases as shown by b-c in FIG. 2, thereby preventing the rear wheels from skidding.

If one of the systems, for example, the front wheel cylinder 31 system, fails, then the gromportioning valve 9
remains in the state shown in the figure and does not operate at all.

When the oil pressure gradually increases in the other system, the plunger 10
The spring seat 27 moves to the right in the drawing against the spring 26, and the spring seat 27 gradually tilts around the part where it contacts the plunger 10', so that the inner surface 24a of the insertion hole formed in the pusher 24 comes into contact with the guide rod 23.

Thereafter, the spring seat 27 is attached to the protruding end 10 of the plunger 10'.
It moves away from a' while sliding on the guide rod 23, and the poppet valve 12 closes itself.

At this time, the spring 26 is acting only on the provisioning valve 8.

In other words, the equation holds true, and one system shows a-b'-c' in Figure 2.
A large braking force as shown in can be obtained, and it is possible to compensate for insufficient braking force when one system fails.

On the other hand, when the master cylinder oil pressure PM increases, the braking force B also increases, and the deceleration α obtained by dividing this braking force by the vehicle weight W
also increases as is clear from the following equation.

B=C・PM・・・・・・(3) (However, C is a constant)∵
g: When the gravitational acceleration/deceleration ratio α/g reaches a certain value determined by the hydraulic control valve inclination angle θ, the ball 50 resists the force of the gravitational acceleration in the direction of the inclination angle θ due to its inertial force. It moves to the middle left and closes the center opening of the valve seat 47.

Therefore, even if the master cylinder oil pressure PM increases further, the oil pressure acting on the piston 48 will be
The master cylinder oil pressure is maintained at the master cylinder oil pressure when the central opening of the chamber 45 is closed, and the confinement pressure PG in the chamber 45 at this time is expressed by the following equation.

The force pushing the piston 48 to the left in FIG.
The force represented by the sum of the spring force F and the spring force y is balanced, and the following is obtained.The spring force F is a force that pushes the Braun jar 10, 10' to the left in Fig. 1, and the spring force F' is a force that pushes the Braun jar 10, 10' to the left in Fig. I'll take it in 1.

On the other hand, the spring forces F and F' are the spring 26 when PM=0, respectively.
, 43, and the value determined by the product of the above-mentioned movement amount ΔX of the piston 48 and the spring constants K1 and K2 of the springs 26 and 43, the relational expression of F and F' is The following formula is obtained.

Therefore, the following equation is obtained from equations (6) and (7).

On the other hand, the critical oil pressure Ps is from the above , and by substituting equation (8) into this equation, it becomes.

The critical oil pressure Ps for the vehicle weight W as shown in FIG.
The following relationship is obtained, and as the vehicle weight W increases, the critical oil pressure P
s increases while increasing its ratio to the vehicle weight W.

Thus, as the vehicle load increases, the rear wheel brake oil pressure PR will increase at the split point b shown in FIG. c", and almost ideal rear wheel brake hydraulic characteristics can be achieved.

By the way, even if the brake system on one side fails during loading, the spring force of the spring 26 acts entirely on the plunger 10 or 10' associated with the normal brake system, as described above, so that the brake system on one side fails. Set wheel brake oil pressure to 2nd
Raise it greatly as shown by a・b"'-C"' in the figure, 1
Insufficient braking force in the event of a system failure can be compensated for even when loading vehicles.

In this way, the hydraulic control valve of the present invention is equipped with a deceleration-sensing valve that increases the critical oil pressure as the vehicle weight increases, making it possible to bring the custom-made front and rear wheel brake force distribution closer to ideal characteristics. It has various features such as a type of hydraulic control valve that is equipped with a provisioning valve that is installed in parallel when the brake hydraulic pressure is insufficient.It is possible to have a wide range of critical hydraulic pressure, and it is also useful for reducing the force on the brake pedal. .

In the hydraulic control valve of the present invention, the master cylinder hydraulic pressure of both systems is guided to the deceleration sensing valve 40, but since there is a switching valve 53 at the confluence of both hydraulic passages, when one system fails, the following happens: This avoids the inconvenience that this system would cause the other normal system 1 to fail, and allows the deceleration sensing valve 40 to function normally with the normal system.

That is, if the system connected to the port 57 fails and no hydraulic pressure is supplied to this port, the switching valve 53
4 maintains the position shown in the figure, and ensures that the normal system oil pressure supplied to port 55 does not flow out to the failure system through port 57 and is reliably supplied to deceleration sensing valve 40.

Additionally, if the system connected to port 55 fails and hydraulic pressure is no longer supplied to this port, the hydraulic pressure supplied to port 57 from the normal system causes the switching valve 53 to operate against the spring 54, causing the port 56 to open. Communication is switched from port 55 to port 57.

The hydraulic pressure guided to the port 57 by the strainer is reliably supplied to the deceleration sensing valve 40 without flowing out from the port 55 to the loss system.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of the hydraulic control valve of the present invention, FIG. 2 is a functional characteristic diagram of the hydraulic control valve of the present invention, and FIG. 3 is a diagram showing the relationship between vehicle weight and critical oil pressure. 1... Housing, 2, 3... Plunger chamber, 4, 6...
...Inlet part, 5,7...Outlet part, 8,9...Proportioning valve, 10,10'...Plunger, 11,1
1'... Blind hole, 12. 12'... Poppet valve body, 13.
13'...Valve seat, 14.14'...Spring, 16,16'
...Through hole, 17, 17'...Through hole, 20.20'...Retainer, 21, 21'...Zeal, 22...Spring seat body, 23...Guide rod, 24...Push, 24a...
... Guide rod insertion hole inner surface, 25 ... Seat plate, 26 ... Spring, 27 ... Spring seat, 28, 31 ... Front wheel cylinder, 29 ... Tandem master cylinder, 30.32
... Rear wheel cylinder, 33 ... Brake pedal,
40... Deceleration sensing valve, 41... Housing, 4
2...Seat plate, 43...Spring, 44...Cylinder chamber, 45
... Ball chamber, 47 ... Valve seat, 48 ... Piston removal valve, 50 ... G hole, 51 ... End cover, 53 ...
...Switching valve, 54...Spring, 55.57...Hydraulic inlet port.

Claims (1)

[Claims] 1 Two systems in which a pair of proportioning valves are installed in parallel, and each of these proportioning valves responds to individual inlet hydraulic pressure against a common spring, thereby limiting the inlet hydraulic pressure and making it the outlet hydraulic pressure. In the hydraulic control valve for piping, the spring is supported by one piston, and a deceleration sensing valve is provided in the cylinder chamber of this piston to confine the inlet hydraulic pressure corresponding to deceleration, and both Between the inlet hydraulic pressure introduction paths, the other inlet hydraulic pressure introduction path is maintained in a state of being blocked by the pressure in one inlet hydraulic pressure introduction path and a spring, and when the system related to the one inlet hydraulic pressure introduction path fails, the other inlet hydraulic pressure is A hydraulic control valve for dual-system piping, characterized in that a switching valve is inserted that is changed to a state in which one of the inlet hydraulic pressure introduction passages is closed by pressure in the introduction passage.